"WHILE SOME US sites still seem to doubt that Intel will introduce an 800MHz front side bus (FSB) for the Springdale chipsets it's currently testing, resellers familiar with the firm's plan confirm that's exactly what's happening with the Pentium 4..... Again, Intel will completely rid itself of Pentium 4s supporting the 400MHz system bus in 2003, and have also told the resellers of the introduction of DDR-400 for its platforms..."
More here: theinquirer.net